PoE Powered Device up to 15W

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Lead Time 20 weeks
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Unit Price:$1.11
Minumum Qty: 490
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Product Information

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The Si3402 integrates all power management and control functions required in a Power-over-Ethernet (PoE) powered device (PD) application. The Si3402 converts the high voltage supplied over the 10/100/1000BASE-T Ethernet connection into a regulated, low-voltage output supply. The optimized architecture of the Si3402 minimizes the solution footprint, reduces external BOM cost, and enables the use of low-cost external components while maintaining high performance. The Si3402 integrates the required diode bridges and transient surge suppressor, thus enabling direct connection of the IC to the Ethernet RJ-45 connector. The switching power FET and all associated functions are also integrated. The integrated switching regulator supports isolated (flyback) and non-isolated (buck) converter topologies. The Si3402 supports IEEE 802.3 Type 1 (Class 3 and below) Powered Device applications. Standard external resistors connected to the Si3402 provide the proper IEEE 802.3 signatures for the detection function and programming of the requested power class. Start-up circuits ensure well-controlled initial operation of both the hotswap switch and the voltage regulator. The Si3402 is available in a low-profile, 20-pin, 5 x 5 mm QFN package. The Si3402-B is a pin-compatible replacement of the obsolete Si3402-A. PCB layouts designed for Si3402-A can be reused with Si3402-B, but some component value changes are required.

• Voice over IP telephones and adapters
• Wireless access points
• Security cameras
• Point-of-sale terminals
• Internet appliances
• Network devices
• High power applications

Symmetry Electronics is an authorized Silicon Labs distributor.


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Pin-compatible replacement for the obsolete Si3402-A
IEEE 802.3 standard-compliant solution, including pre-standard (legacy) PoE support
Highly-integrated IC enables compact solution footprints
Minimal external components
Integrated diode bridges and transient surge suppressor
Integrated switching regulator controller with on-chip power FET
Integrated dual current-limited hotswap switch
Programmable classification circuit
Incorporates switcher EMIreduction techniques.
Supports non-isolated and isolated switching topologies
Comprehensive protection circuitry
Transient overvoltage protection
Undervoltage lockout
Early power-loss indicator
Thermal shutdown protection
Foldback current limiting
Low-profile 5 x 5 mm 20-pin QFN


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